Metal nanoflower and preparation method thereof

Abstract

The invention discloses a metal nanoflower and a preparation method thereof, comprising the following steps: dissolving a metal organic salt precursor, cuprous chloride, a reducing agent and a dispersant in a benzyl alcohol solution to obtain a reaction liquid; transferring the reaction liquid to a specific reactor for pre-stirring treatment, heating to a predetermined temperature for reaction, and obtaining the metal nanoflower, wherein the metal organic salt precursor is ruthenium acetylacetonate, and the molar ratio of the metal organic salt precursor to cuprous chloride is (2-6):1. The preparation method has fewer synthetic reaction steps, simplifies the preparation method, and the prepared metal nanoflower has a multi-channel flower-like structure, improves its catalytic activity, and has good dispersibility.

Description

Technical Field

[0001] The invention belongs to the technical field of nano materials, and in particular relates to a metal nano flower and a preparation method thereof. Background Art

[0002] Precious metal nanoparticles have excellent physical and chemical properties and have very broad application prospects in the fields of nanocatalysis, photothermal conversion, energy storage, etc. Morphology control can effectively change the physical and chemical properties of nanomaterials, which is of great significance for the practical application of nanomaterials. Therefore, a simple and easy method for preparing nanomaterials with high yield and high catalytic activity is one of the important goals currently pursued in the field of nanomaterial preparation. In recent years, nanoparticles are considered to have huge specific surface area and unsaturated coordination active sites, and therefore have extremely high application potential in the field of catalysis.

[0003] Chinese patent publication number CN112658276A discloses a method for preparing heterogeneous precious metal sea urchin-shaped nanocrystals, and specifically discloses adding citric acid-stabilized gold seeds into an acidic chloroauric acid solution, followed by adding silver nitrate and ascorbic acid to generate sea urchin-shaped nanocrystals, adding hexadecyltrimethylammonium bromide to stabilize the particles after the reaction, and using this crystal as a substrate to achieve synergistically enhanced SERS ultra-high sensitivity detection under the double superposition effect.

[0004] Chinese patent publication number CN107931628B discloses a method for preparing a self-loaded flower-like hierarchical structured nano precious metal material, and specifically discloses the use of a chemical self-assembly method to co-assemble dopamine and a heteropoly acid to form a flower-like hierarchical structure, which is then dispersed in a noble metal-soluble salt solution, and the catechol groups of the flower-like hierarchical structure are used to in-situ reduce the precious metal to prepare a loaded flower-like hierarchical structured nanomaterial.

[0005] Both of the above preparation methods can be used for the synthesis and preparation of precious metal nanoparticles with high catalytic activity, but the synthesis steps require more than two steps, the preparation process is relatively cumbersome, which reduces the preparation efficiency and increases the preparation cost. Summary of the invention

[0006] The purpose of the present invention is to solve the problems in the background technology and to provide a metal nanoflower and a preparation method thereof.

[0007] To achieve the above object, the present invention proposes a method for preparing metal nanoflowers, comprising the following steps:

[0008] Dissolving a metal organic salt precursor, cuprous chloride, a reducing agent and a dispersant in a benzyl alcohol solution to obtain a reaction solution; transferring the reaction solution to a specific reactor for pre-stirring treatment, heating to a predetermined temperature for reaction, and obtaining metal nanoflowers;

[0009] The metal organic salt precursor is ruthenium acetylacetonate, the molar ratio of the metal organic salt precursor to cuprous chloride is (2-6):1, and the specific reactor includes but is not limited to a glass reaction bottle with a magnet.

[0010] Preferably, the total concentration of the metal organic salt precursor and cuprous chloride in the reaction solution is 0.1-6 mg / ml.

[0011] Preferably, the reaction solution is pre-stirred in the specific reactor for 1 to 5 hours.

[0012] Preferably, the reaction solution is heated to a predetermined temperature of 120 to 180° C. for reaction, and the reaction time is 1 to 5 hours.

[0013] Preferably, the reducing agent is one or two of ascorbic acid, glucose, urea, citric acid and sodium borohydride.

[0014] Preferably, the dispersant is polyvinyl pyrrolidone.

[0015] Preferably, the molecular weight of the polyvinyl pyrrolidone is 10,000-80,000.

[0016] Preferably, the concentration of the dispersant in the reaction solution is 1.0×10 -4 ~1.2×10 -3 mol / L.

[0017] The present invention also provides a metal nanoflower prepared according to the preparation method of the metal nanoflower.

[0018] Preferably, the metal nanoflower has a multi-channel flower-like structure.

[0019] The present invention has the following beneficial effects:

[0020] 1) The synthesis reaction has fewer steps. Ruthenium acetylacetonate, cuprous chloride, a reducing agent and a dispersing agent are dissolved in a benzyl alcohol solution as a reaction solution, and then added into a specific reactor for direct synthesis reaction, so that the synthesis steps are simplified to one step, the preparation method is simplified, the preparation efficiency is significantly improved and the preparation cost is reduced.

[0021] 2) Metal nanoflowers have a multi-channel flower-like structure that can promote mass transfer in solutions, and the surface of their flower-like structural units has more unsaturated coordination and active sites, which can effectively improve their catalytic activity.

[0022] 3) The components of metal nanoflowers are adjustable, and their sizes are uniform and their dispersion is good.

[0023] The features and advantages of the present invention will be described in detail through embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a TEM image of the Ru2Cu nanoflower prepared in Example 1 of the present invention.

[0025] Figure 2 This is the energy spectrum of the Ru2Cu nanoflower prepared in Example 1 of the present invention.

[0026] Figure 3 This is a TEM image of the Ru3Cu nanoflower prepared in Example 2 of the present invention.

[0027] Figure 4 This is the energy spectrum of the Ru3Cu nanoflower prepared in Example 2 of the present invention.

[0028] Figure 5 This is a TEM image of the Ru4Cu nanoflower prepared in Example 3 of the present invention.

[0029] Figure 6 This is the energy spectrum of the Ru4Cu nanoflower prepared in Example 3 of the present invention.

[0030] Figure 1 Figure b is an enlarged view of Figure a; Figure 3 Figure e in the middle is an enlarged view of Figure d; Figure 5 The middle figure h is an enlarged view of figure g. DETAILED DESCRIPTION

[0031] Example 1

[0032] This embodiment provides a method for preparing metal nanoflowers: 8 mg of ruthenium acetylacetonate, 1 mg of cuprous chloride, 15 mg of citric acid, 100 mg of polyvinyl pyrrolidone (M w =55000) was added into 5 ml of benzyl alcohol solution, stirred for 3 h to fully dissolve ruthenium acetylacetonate and cuprous chloride to obtain a reaction solution, the reaction solution was transferred to a 25 ml glass reaction bottle with a magnet, heated to 160°C, and reacted for 3 h at a stirring rate of 330 rpm. After the reaction was completed, a small amount of the liquid in the glass reaction bottle was centrifuged to obtain Ru2Cu nanoflowers.

[0033] Example 2

[0034] This embodiment provides a method for preparing metal nanoflowers: 12 mg of ruthenium acetylacetonate, 1 mg of cuprous chloride, 15 mg of citric acid, 100 mg of polyvinyl pyrrolidone (M w=55000) was added into 5 ml of benzyl alcohol solution, stirred for 3 h to fully dissolve ruthenium acetylacetonate and cuprous chloride to obtain a reaction solution, the reaction solution was transferred to a 25 ml glass reaction bottle with a magnet, heated to 160°C, and reacted for 3 h at a stirring rate of 330 rpm. After the reaction was completed, a small amount of the liquid in the glass reaction bottle was centrifuged to obtain Ru3Cu nanoflowers.

[0035] Example 3

[0036] This embodiment provides a method for preparing metal nanoflowers: 16 mg of ruthenium acetylacetonate, 1 mg of cuprous chloride, 15 mg of citric acid, 100 mg of polyvinyl pyrrolidone (M w =55000) was added into 5 ml of benzyl alcohol solution, stirred for 3 h to fully dissolve ruthenium acetylacetonate and cuprous chloride to obtain a reaction solution, the reaction solution was transferred to a 25 ml glass reaction bottle with a magnet, heated to 160°C, and reacted for 3 h at a stirring rate of 330 rpm. After the reaction was completed, a small amount of the liquid in the glass reaction bottle was centrifuged to obtain Ru4Cu nanoflowers.

[0037] Dispersibility and structural size test of metal nanoflowers: TEM samples of Ru2Cu nanoflowers, Ru3Cu nanoflowers and Ru4Cu nanoflowers prepared in Example 1, Example 2 and Example 3 were prepared respectively, and the morphologies were observed by transmission electron microscopy. The TEM images and energy spectra of the three metal nanoflowers are shown in Figures 1 to 6 .

[0038] Depend on Figure 1 (a, b) It can be seen that the Ru2Cu nanoflower has a flower-like structure with a size of about 45nm. Figure 2 It can be seen that the elements of Ru2Cu nanoflowers are evenly dispersed; Figure 3 (d, e) It can be seen that the Ru3Cu nanoflower has a flower-like structure with a size of about 45nm. Figure 4 It can be seen that the elements of Ru3Cu nanoflowers are evenly dispersed; Figure 5 (g,h) It can be seen that the Ru4Cu nanoflower has a flower-like structure with a size of about 45nm. Figure 6 It can be seen that the elements of Ru4Cu nanoflowers are evenly dispersed.

[0039] The above embodiments are intended to illustrate the present invention, not to limit the present invention. Any solution that is a simple transformation of the present invention belongs to the protection scope of the present invention.

Claims

1. A method for preparing metal nanoflowers, characterized in that , including the following steps: Dissolving a metal organic salt precursor, cuprous chloride, a reducing agent and a dispersant in a benzyl alcohol solution to obtain a reaction solution; transferring the reaction solution to a specific reactor for pre-stirring treatment, heating to a predetermined temperature of 120 to 180° C. for reaction for 1 to 5 hours to obtain metal nanoflowers; The metal organic salt precursor is ruthenium acetylacetonate, the molar ratio of the metal organic salt precursor to cuprous chloride is (2-6):1, the total concentration of the metal organic salt precursor and cuprous chloride in the reaction solution is 0.1-6 mg / ml, the dispersant is polyvinyl pyrrolidone, and the concentration of the dispersant in the reaction solution is 1.0×10 -4 ~1.2×10 -3 mol / L, and the specific reactor is a glass reaction bottle with a magnet.

2. The method for preparing the metal nanoflowers according to claim 1, wherein: The reaction solution is pre-stirred in the specific reactor for 1 to 5 hours.

3. The method for preparing the metal nanoflowers according to claim 1, wherein: The reducing agent is one or two of ascorbic acid, glucose, urea, citric acid and sodium borohydride.

4. The method for preparing the metal nanoflowers according to claim 1, characterized in that: The molecular weight of the polyvinyl pyrrolidone is 10,000-80,000.

5. A metal nanoflower prepared according to the method for preparing metal nanoflowers according to any one of claims 1 to 4.

6. The metal nanoflower according to claim 5, characterized in that: The metal nanoflower has a multi-channel flower-like structure.

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